So I just got a Mark III and want to hook it up to my Marshall 1960A cab 16 ohm. So do I take two speaker cables plug them into the 2x 4 ohm outputs in the back of the amp and put them in the two inputs in the back of the cab 8 ohm stereo (the cab would be switched on stereo) or do i run on mono and plug into the 4 ohm in the cab...sorry if this is a stupid question but I am confused (new to boogie) up until now the cab was on mono and I plugged into the left input (16 ohm) and the amp output was plugged into 8 ohm. Hope I didn't screw anything up.

viendette wrote:So I just got a Mark III and want to hook it up to my Marshall 1960A cab 16 ohm. So do I take two speaker cables plug them into the 2x 4 ohm outputs in the back of the amp and put them in the two inputs in the back of the cab 8 ohm stereo (the cab would be switched on stereo) or do i run on mono and plug into the 4 ohm in the cab...sorry if this is a stupid question but I am confused (new to boogie) up until now the cab was on mono and I plugged into the left input (16 ohm) and the amp output was plugged into 8 ohm. Hope I didn't screw anything up.

Yes. The two speaker jacks on the amp marked as "4 ohm" want to see an 8 ohm load in each jack, for a total load of 4 ohms. The label is misleading, as many think you are s'posed to plug a 4 ohm cab into each jack. Not so.
The 8 ohm amp output into the 16 ohm cab is a safe mismatch.

a Y cable? Dude, dont use y cables for connecting cabs. If you are at a point of having to use y cable for connecting cabs, then you have either the wrong head or the wrong cab. Get one that works. One cable for each cab to the head. If both of your cabs are 8 ohms, plugging into both 4 ohm jacks is safe. If you have a 16 ohm cab and a 8 ohm cab, it will also be safe. If you have a 4 ohm cab and a 8 ohm cab, expect to see smoke.

You can use the 4 ohm jack of your head into the 16 ohm input of the cab. Again, no need for y cables to connect cabs...ever.

I have to warhead cabs hooked into my mark III. On the 4x12, I have a selector switch for the ohm load...4/16 mono, and 8 ohm stereo. I have to put the switch at 16 ohm mono in order to run the 2x15 cab as it defaults at 8 ohm. With the 2 cabs in that config, the amp will be pushing around 5 ohms. If I were to put the switch at 4 ohm, the overall load would be about 2 ohms which will fry the head.

Since you have an 8 ohm and 4 ohm jack, using either one of the jacks into a 16 ohm cab will be safe.

viendette wrote:So I just got a Mark III and want to hook it up to my Marshall 1960A cab 16 ohm. So do I take two speaker cables plug them into the 2x 4 ohm outputs in the back of the amp and put them in the two inputs in the back of the cab 8 ohm stereo (the cab would be switched on stereo) or do i run on mono and plug into the 4 ohm in the cab...sorry if this is a stupid question but I am confused (new to boogie) up until now the cab was on mono and I plugged into the left input (16 ohm) and the amp output was plugged into 8 ohm. Hope I didn't screw anything up.

You dont need to use 2 cables for one head with a stereo Cab.

Just run from the 8 ohm out on the head into the 16 ohm input on the cabinet and it will power all 4 speakers.

Technically it would work, running the 2-cables out of the amp and powering each half of the stereo cab, but can't see any point in doing it that way as the amp itself is not Stereo.

It has nothing to do with stereo. It's about matching impedence. Running two cables in stereo into both 4 ohm inputs on the head would be the correct match. The 16 ohm mono on the cab into the 8 ohm input on the head is a safe mis-match but will alter the sound and feel somewhat. This isn't a bad thing either. You may like the extra sag of the 16 ohm connection.

ryjan wrote:It has nothing to do with stereo. It's about matching impedence. Running two cables in stereo into both 4 ohm inputs on the head would be the correct match. The 16 ohm mono on the cab into the 8 ohm input on the head is a safe mis-match but will alter the sound and feel somewhat. This isn't a bad thing either. You may like the extra sag of the 16 ohm connection.